The __builtin_clz* and __builtin_ctz* built-in functions are specified to have undefined results for zero inputs, but on targets that support these operations in a way that provides well-defined results for zero without loss of performance, it is a good idea to avoid optimizing based on that undef behavior. More...

Determines whether a given calling convention is valid for the target.

A calling convention can either be accepted, produce a warning and be substituted with the default calling convention, or (someday) produce an error (such as using thiscall on a non-instance function).